Choline (2-hydroxyethyl-trimethyl ammonium hydroxide), is usually classified to compound vitamin B group (Vitamin B4). It is a kind of low molecular weight organic compounds that necessary for animal body to maintain physiological function, which can be synthesized in animal body but often need add in feed, is the most monomer vitamin which be added in feed. In animal bodies it can adjust the metabolism and transformation of fat, prevent fat from aggradation and tissue denaturation in liver and kidney, promote the re-generation of amid acid, enhance the utilization ratio of amid acid and save a part of methonine.

Choline choride is the most common and most economical form, and mainly used additives to compound in feed. Choline Chloride has 50% and 60% corn cob base, 50% silica base, 70% and 75% Liquid. 50% corn cob base and 75% are most popular and economical. Except moisture absorption and deliquescence it also damage other vitamin in use process. So it must be added in last process. Especially it damage the vitamin A, vitamin D and vitamin K fast when together with metal element. So multidimensional products cannot be added choline and the compound feed with choline must be used in time.